<template>
  <div>
      <router-link tag="div" to="/" class="header-abs" v-show="showAbs">
          <div class="iconfont icon-fanhui header-abs-back"></div>
      </router-link>
      <div 
      class="header-fixed" 
      v-show="!showAbs"
      :style="opacityStyle"
      >
           <router-link to="/">
             <div class="iconfont header-fixed-back">&#xe624;</div>
           </router-link>
          景点详情
      </div>
  </div>
</template>

<script>
export default {
name:'DetailHeader',
data() {
    return {
        showAbs:true,
        opacityStyle:{
            opacity:0
        }
    }
},
methods: {
    handleScroll(){
        const top = document.documentElement.scrollTop
        if(top > 60){
            let opacity = top / 140
            opacity = opacity > 1 ? 1 : opacity
            this.opacityStyle = { opacity }
            this.showAbs =false
        }else{
            this.showAbs =true
        }
    }
},
activated(){
    window.addEventListener('scroll',this.handleScroll)
},
deactivated() {
    window.removeEventListener('scroll',this.handleScroll)
},
}
</script>

<style lang="stylus" scoped>
   @import '~styles/varibles.styl'
  .header-abs
    position: absolute
    left: .2rem
    top: .2rem
    width: .8rem
    height: .8rem
    line-height: .8rem
    border-radius: .4rem
    text-align: center
    background: rgba(0, 0, 0, .8)
    .header-abs-back
      color: #fff
      font-size: .4rem
  .header-fixed
    z-index: 2
    position: fixed
    top: 0
    left: 0
    right: 0
    height: $headerHeight
    line-height: $headerHeight
    text-align: center
    color: #fff
    background: $bgColor
    font-size: .32rem
    .header-fixed-back
      position: absolute
      top: 0
      left: 0
      width: .64rem
      text-align: center
      font-size: .4rem
      color: #fff
</style>